Drill-feeding device



April 1, 19.30. c c, HANSEN 1,753,007

DRILL FEEDING DEVICE Filed Nov. 1? 192'? w 7 II VVTOR.

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Patented Apr. 1, 1930 umrao STATES PATENT OFFICE CHARLES C. HANSEN, OF EASTON, PENNSYLVANIA, ASSIGNOR T INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY DRILL-FEEDING DEVICE Application filed November 17, 1927. Serial No. 233,856.

This invention relates to rock drills, but more particularly to a feeding device for fluid actuated rock drills of the drifter type.

The objects of the invention are to maintain a suitable pressure on the rock drill for feeding it towards the Work in accordance with the penetration of the drill steel into the material being drilled, and to facilitate the oper- V ation of withdrawing the drifter from the 1 work.

Other objects will be in part obvious and in part pointed out hereinafter, and to all of these ends the invention consists of the combination of elements and arrangement of parts substantially as hereinafter described and claimed and illustrated in the accompanying drawings, in which Figure 1 is a longitudinal side elevation of a drifter and its shell equipped with a device constructed in accordance with the practice of the invention,

Figure 2 is an enlarged longitudinal sectional elevation of the device, and

Figure 3 is a transverse view of a detail taken through Figure 2 on the line 3-3 looking' in the direction of the arrows.

Referring more particularly to the drawings, A generally designates a rock drill having a cylinder 13 and a front head C. A head block D forms a closure for the rearward end of the cylinder and also acts as a seat fora back head E. The parts so far described comprisethe casing of the rock drill A and may be held in suitable operative relation by means of spring pressed side bolts F.

Disposed in the front end of the front head C is a working implement, such as a drill steel G for drilling holes H in the rock J.

The rock drill A is provided with the usual shell K wherewith it cooperates slidably in a well known manner. The shell K carries a conical member L which may be clamped to suitable clamping means carried by a column or quarry bar (not shown) whereby the rock drill may be supported relatively to the rock J.

In accordance with the present invention, means are provided for utilizing pressure p fluid to advance the rock drill A towards the so work, such as the rock J, and for retracting ittherefrom. These means in the present instance comprise a feeding cylinder 0 secured tothe rearward end of the shell K bymeans of bolts P and a diflerential piston Q, which extends slidabl into the feeding cylinder 0.

The piston d preferably consists of a cylindrical block R disposed. on a reduced end S of a piston rod T. In order to prevent leakage of pressure fluid along the piston Q, a cup leather U is disposed at the inner end of the block R and is pressed against the wall of the feeding cylinder O by a bushing V which extends into the cup leather U and is forced against a shoulder W of the rod T. A

nut X screwed on the end of the reduced end S serves to clamp the piston parts in operative position. 7

The piston rod T in this instance is attached to the back head E through which it extends and has a flange Y at its innermost end to prevent withdrawal of the piston rod T from the back head E.

The rearward end of the feeding cylinder 0 is sealed by a head Z which is clamped to the feeding cylinder 0 by bolts 6. At the opposite or inner end of the feeding cylinder 0 isdisposed a head '0 through which the piston rod '1 slides and. has a flange cl extending betweenthe rearward end of the shell K and the inner 'endofthe feeding cylinder 0.

Any suitable means may be provided for preventing leakage of pressure fluid through the head 0. The means employed for this purpose in the present instance consists of a packing e which encircles the piston rod T, and a gland 7 whichextends into a recess 9 of the head 0 wherein the packing is disposed.

Preferably the inner end It, or in other words, the end of the smaller area of the piston Q, is constantly exposed to pressure fluid so that in the absence of pressure fluid in the rearward end of the feeding cylinder O'the rock drill will automatically be withdrawn from the work. To this end a block j disposed about the inner end of the feeding cylinder 0 is provided with a supply chamber which may encircle the feeding cylinder 0. Pressure fluid is conveyed to the supply chamber is from a source of supply (not shown) through a connection 0. The chamber is comthe percussive element of the rock drill AL Suitable means are provided for selectively exposing the rearward end 8 ofthe piston R to pressure fluid to force the rock drill A towards the work in accordance with the penetration of the drill steel into the rock J. To this end a throttle valve tis disposed-in the back'head E and has a lever u whereby said,

throttle valve may be manipulated. The throttle valve may be of the tapered. type and has a centralaperture-'1) and a port M which may communicate with the throttle valve 1 through a passage 00 formed in the back head E and the head block D.

The port to in the throttle valve 25 may be of a width to simultaneously register with both a port 00 and a passage y in the back head E, The passage 1 communicates at its outlet end with an annular groove 2 preferably formed in the head block D for conveying pressure fluid to a supply passage 2 extending throughout the length of the piston rod T.

In order to enable pressure fluid to exhaust from the rearward end of the feeding cylinder 0, a passage 3 is formed in the back head E to establish communication between the annular passage 2 and the throttle valve chamber 4. In what may be' termed the closed position of the throttle valve 25, the passage 3 will register with the port to in the throttle valve which communicates with a port 5. This port 5 registers with an exhaust passage 6 leading to the atmosphere.

, Any suitable-and convenient means may be provided for centralizing. the back head E with respect to the head block D. These means in the present instance consist of a projection 7 carried by the back head E and extending into a recess 8 in the rearward end of said block D. Preferably a water tube 9 and its plug 10 are so disposed in the back head E that said water tube 9 will extend a through the projection 7 and thence through the head block D and the cylinder A for conveying cleansing liquid to the drill steel G.

In order to prevent the impact of the rock drill against any portion of the shell K, a

rubber buffer 11 is inserted in a hollow lug 12 carried by the cylinder B. The buffer 11 extends rearwardly of the cylinder B and is adapted to abut a shoulder 13 in the rearward end of the shell K to limit the rearward movement of the drill A with respect to said shell K.

The operation of the device is as follows: With the throttle valve r in its open position, pressure fluid will flow into the cylinder B to set the hammer piston (not shown) in operation. In this open position of the throttle valve 7', pressure fluid will also flow therefrom through the passage am into the aperture-cot the valve t. If then, it be desiredto force the rock drill in the direction of the work, the throttle valve t may be opened to establish communication between the passages 00 and y. In this position of the throttle valve 7 t, pressure fluid will flow through these passages and through the annular passage 2 and the passage 2 into the rearward end of the feeding cylinder 0. Due to the differential of area between the ends 8 and h of the piston, the pressure fluid acting against the larger end 8 will predominate over that acting against the end It and will thus exert an effective pressure on the rearward end of the piston 1 sufficient to hold the drill firmly to the work.

After the drill hole H has been completed, the throttle valve t may be rotated into a position to cut off communication between the passage as and y. In this position of the throttle valve 25, communication may also be established between the passages 3 and 6 by the passage 5, thus providing a free path for the exhaust of pressure fluid from the rear-' ward end of the feeding cylinder O to the atmosphere. The pressure fluid acting against the inner or smaller end it of the piston R will then act to retract the drill A from the work.

In order to prevent a too rapid withdrawal of the drill from the work, the pressure fluid from the rearward end of the feeding cylinder 0 may be exhausted gradually therefrom. This may be accomplished by .proper manipulation of the throttle valve 25.

' I claim:

1. The combination with a rock drill having a back head and a shell, of a piston rod secured to the back head and having a piston thereon, a feeding cylinder secured to the shell, a supply passage in the piston rod to convey pressure fluid to the rearward end of the feeding cylinder, a fluid supply line in in constant communication with the cylinder forwardly of the piston, a throttle valve in the back head controlling the pressure fluid to thedrill, means for admitting a source of fluid supply to said throttle valve, and a second throttle valve in the back head adapted to selectively communicatesaid first mentioned throttle valve with the supply passage in the piston rod or to communicate the said supply passage with the atmosphere.

2. The combination with a rock drill having a back head and a shell, of a piston rod secured to the back head and having a piston thereon, a feeding cylinder secured to the shell, a supply passage in the piston rod opening into the rearward end of the feeding cylinder, at fluid supply line in constant communication with the cylinder forwardly of the piston, a throttle valve in the hack head controlling the admission of pressure fluid to the drill, a flexible fluid supply connection leading to said throttle valve, a second throttle valve in the back head, and an annular passage in the back head adapted to register with the second throttle valve and with the supply passage, said second throttle valve being adapted to selectively communicate said first throttle valve with said annular passage or said annular passage with the atmosphere.

3. The combination with a rock drill having a back head and a shell, of a piston rod secured to the back head and having a piston thereon, a feeding cylinder secured to the shell, a supply passage in the piston rod openinointo the rearward end of the feeding cylin der, a supply chamber in constant communication with the cylinder forwardly of the piston and with a source of supply fluid, a throttle valve in the hack head controlling the admission of pressure fluid to the drill, a flexible connection between the supply chamber and said throttle valve, a second throttle valve in the back head, and an annular passage in the back head adapted to register with the second throttle valve and with the supply passage, said second throttle valve being, adapted to selectively communicate said first throttle valve with said annular passage or said annular passage with the atmosphere.

In testimony whereof I have signed this specification.

CHARLES C. HANSEN. 

